Towards an algebraic approach to interoperability

The Warfighter Information Network (WIN) will be an internet comprising a set of heterogeneous networks. Thus, it is essential to develop necessary tools that facilitate proper deployment and operation of WIN through expeditious interoperability testing and interface development. The communication, control, and management systems of a network (or an internet) essentially comprise a set of concurrent communicating sequential processes (CSP) that ensure the proper delivery of information from a sender to a receiver. The objective of this paper is to report the preliminary results of a study on the use of CSP algebra for developing algebraic definitions and criteria for interoperability of two distinct networks. It specifically focuses on the CSP models for a single network and an internet, and the criteria for interoperability of two distinct subnets of an internet. The preliminary results of this exercise indicate that: The end-to-end behavior of a correct protocol resembles an unbounded buffer process whose performance satisfies QoS requirements of the network; in principle, two distinct subnets with correct protocols are interoperable (or can be made so); at least part of the protocols of different subnets of an internet should be common; it is desirable that the subnets' management (and control) systems share a common application programming interface.